He contrasted the Welsh efforts under Andrew RT Davies with the "highly disciplined" campaign in Scotland.

Scottish Tory leader Ruth Davidson did not "pretend" she was going to become first minister but set out to offer an effective opposition, Mr Crabb said.

He was speaking a fringe meeting at the Tory party conference in Manchester.

The Preseli Pembrokeshire MP said: "Ruth ran an incredibly disciplined, highly disciplined, effective campaign in Scotland, not pretending that she was going to become first minister, but basically making the point that Scotland needs a decent opposition.

"People really seemed to respond to that. The message that we were running with in Wales, if I'm honest, seemed a bit too fragmented, a bit too confused.

"At times we were trying to convince people in Wales that we were about to topple the first minister and form a majority government. No one believed we were in a position to do that."

The Welsh Conservatives failed to capitalise on the party's gains at the 2015 general election, losing three of their 14 Senedd seats and coming third behind Labour and Plaid Cymru.